A 'true' tale of love and honour killing in Jordan is a runaway bestseller, yet writes Malcolm Knox, many doubts surround the story.

Around Chicago's Midway Airport the houses are small and neat and a good example of how the American working classes can live in a style that would be the envy of most other people in the world.

The last south-western stop on Chicago's famous "El", or elevated train line, Midway is a modest neighbourhood but a well-tended one, its regular brick and clapboard cottages blighted only by the low roar of jets coming into the city's second airport.

It is a long way from the "unforgiving desert whose oases have blossomed into cities . . . [where] the desert continues to blow in", as Norma Khouri describes Jordan in the prologue to her bestselling memoir, Forbidden Love.

Khouri's book, a publishing sensation in Australia and around the world, narrates her friendship with "Dalia", a spirited and ambitious girl whose eyes "betrayed a hint of conspiratorial glee". According to the book, Khouri and Dalia opened a unisex hair salon, N & D's, in the Jordanian capital of Amman in 1990. They worked under the eye of male relatives, but secretly Dalia, a Muslim, fell in love and pursued a relationship with "Michael", a Christian client.

When the men of her family discovered this chaste but taboo affair across religious lines, Dalia's father stabbed her to death. A terrified but determined Khouri was smuggled out of the country with Michael's help. She wrote her book in internet cafes in Athens, moved to Australia with the help of her publisher Random House, and now lives in a secret location in Queensland because she fears for her life.

Some of Forbidden Love's detailing of Amman is fanciful and some of it plainly wrong, with suburbs in the wrong place, nonexistent hotels and confused geography (on page 2, Jordan is erroneously described as "bordered by" Kuwait).

These mistakes are understandable given that Khouri has never lived in Jordan since she was a young child and had, in fact, led a comparatively normal life as a married mother of two in those south Chicago suburbs before moving to Australia.

The unravelling of Khouri's story began in Jordan, where the peak lobby group for women's rights received an anonymous email from her three years ago. Addressed to the Jordanian National Commission for Women, Khouri's email asked for a bank account into which she could deposit money that might arise from her upcoming book.

At this point Khouri knew she might have a goldmine on her hands. She had sent her manuscript to a New York agent, Christy Fletcher, who placed it with 16 publishers around the world. The book, about the murder of Khouri's childhood friend Dalia, was going to draw global attention to the barbarity of honour killing. It was also going to put considerable wealth at Khouri's disposal.

The director of the women's commission in Amman, Amal al-Sabbagh, ignored the request: "I don't respond to anonymous emails and I didn't know anything about this book, so how could I give it our endorsement?"

After the book's massively successful publication - it has sold an estimated 250,000 copies around the world - Khouri continued to seek cover by soliciting donations for the commission, which remained unconvinced.

"When I got the book I thought she doesn't know anything about Jordan," says al-Sabbagh. "It sounded fake. If this killing had really happened, we would know about it. Jordan is a small place and this is our job - people eventually hear about these things. And we knew nothing about this."

Other matters in the book aroused al-Sabbagh's suspicion. Khouri's descriptions of Jordanian law were exaggerated and often incorrect. Opinions and myths were presented as factual statements.

"I began to think that this wasn't a Jordanian," al-Sabbagh says.

Touring the world publicising her book, Khouri was also raising eyebrows with her perfect, American-accented English, after she had presented herself, in her book, as a feisty but oppressed ingenue. She said she had been sent to an American school in Jordan where she learned English. No records of such attendance have been found.

In the summer of last year al-Sabbagh and a colleague, Rana Husseini, set to work researching Khouri's claims. They found 73 errors and exaggerations in the book. Most damning, the unisex salon, which forms the focus for the book's action, set in the early and mid-1990s, could not exist by law and was not remembered by any Amman hairdressers or their union.

On September 15 last year al-Sabbagh submitted this dossier of errors to Khouri's publishers in the United States and Australia. Random House Australia replied: "Following our discussions with Norma we are satisfied that, while some names and places have been changed to protect individuals' identities ... Forbidden Love is a true and honest account of her experiences."

Khouri, who enclosed a letter to the commission, along with individual rebuttals of all 73 points. "Forbidden Love is not fiction," she wrote, going on to attack the commission. "Is it not enough that her father received nothing more than a slap on the wrist for her murder ... now you wish me to say that she never existed in the first place ... and for what ... the 'image of Jordan'. I am angered to see that you are more concerned for the 'image of Jordan' than for the many innocent victims of honour killings each year in your country."

Her responses to the commission's points were laced with emotion - "I was there" - but she conceded she had changed many names and places and altered timelines to "protect the innocent".

She concluded the letter: "I intend to make sure that Dalia [which she now acknowledged was a made-up name] continues to exist, not only in my heart and in my memories ... but in the hearts and minds of all who read this book, and all who hear me speak."

This only spurred al-Sabbagh to further action.

"It was totally crazy. She accused us of only defending Jordan's reputation, when we had to defend the reputation of Jordanian women against what she wrote," al-Sabbagh says. "She ruined the reputation of Jordanian women, saying they were imprisoned in their homes and so on. Jordanian women have excellent education levels that are gradually being translated into participation in the workforce. Her tone is that all Jordanian women live under these traditional practices, which is wrong."

Al-Sabbagh was angered enough to inquire into Khouri's family background and discovered, through official records, that Khouri had not left the country in the late 1990s or 2000 as she claimed. In fact, she had entered Jordan on a US passport in November 2000, registering as the wife of John Toliopoulos, a Greek-American, who she had married in Chicago in 1993.

Independently, the Herald had researched Khouri and found a string of Chicago addresses where she had supposedly lived through the 1990s.

In February the Herald contacted Khouri's publisher, Fiona Henderson of Random House Australia, who rubbished the claims but did contact Khouri. It was important to address the matter, said Henderson, as "someone else will come asking at some stage so we should sort it out now".

In a telephone call in February Khouri told the Herald that she had never lived in the US. The American paper trail, she said, had been fabricated to trick the Jordanian immigration department into giving her travel documents.

"Yes, I have paperwork that shows that I was married to [Toliopoulos]," she said. "This was to get my Jordanian passport without my father's involvement."

Friends, she said, including the book's Michael, the man who had fallen in love with Dalia, had "set up an address in America as though I was there. To get out, I had to show I was married to a foreigner in a foreign country."

She conceded that she had returned to Jordan for a week in November 2000, a place to which, in her book and in interviews, she says she could not go for fear of her life. But she said she went back only to obtain travel documents, and she could "prove" she never had an American passport.

The truth is that to maintain the subterfuge she was creating, Khouri had to travel on Jordanian papers, rather than the American passport that would give her away. As a Jordanian by birth, she was entitled to a Jordanian identity document. She spent her short time in Amman compiling research for her book. (This answers al-Sabbagh's claim that some buildings and establishments named in the book existed later than the book's timeframe.)

In March, Khouri gave the Herald a letter from an Australian immigration agent saying she had travelled to America last year for a publicity tour on a special temporary visa. If she had a US passport, she said, she wouldn't need such a visa.

This was the "proof" she had promised that she had never lived in America. It is a kind of logical inference: why get a US visa if you already have a US passport? But one doesn't preclude the other. US consulates do not check if visa applicants already hold passports. It would be illogical in most cases. But not in Khouri's.

Her explanation for the paper trail was convincing as long as it remained only a paper trail. But when the Herald visited Chicago in July, a different story emerged. Occupants of Khouri's former homes said they still received mail for her and Toliopoulos. One neighbour said she thought Khouri and Toliopoulos had been evicted a few years ago from their flat. Then, in South Long Street, a leafy but down-market end of the Midway area, several former neighbours remembered Khouri and spoke well of her mother, Asma, and brother, Will, who still live there.

The house, which Asma bought with Norma and her other daughter, Diana, in 1990, is technically a townhouse but is actually the middle part of a brick triplex. Inside, it is small and dark but clean, and the shelves and television are weighed heavily with photographs of Norma Khouri and her children, Christopher and Zoe. They are sorely missed.

Will Bagain says he misses Khouri and her children and hopes to see her again. Khouri's mother Asma, now 64, is a retired nurse and suffers from diabetes and a heart condition. "I have no idea why they left," says Asma. "The mother's always the last to know ... They hurt me big. I miss them so much. But Norma always kept deep secrets. She kept things to herself. If I want to send her a message, it is that everyone at home is okay and can she please send pictures of my grandchildren."

Asma owns a copy of Forbidden Love - published in the US as Honor Lost - but her ideas of where and why Khouri went appear sketchy. There is a suggestion of Khouri and Toliopoulos having had money problems, and the Bagains do not like the Toliopoulos family. But, as Will says: "One day she was there, the next she was gone."

They have no notion of what a literary celebrity Khouri has become. In a survey of 23,000 readers last year, Angus and Robertson found that Forbidden Love was ranked No.55 out of readers' favourite 100 books of all time, from any culture. It has spawned a publishing trend, bestselling first-person accounts of women fleeing barbaric, often Muslim, cultures to the West. Most of these books are, in all likelihood, true and honest records. But it is also likely that their publishers have taken the author's word on faith, as Random House and 15 others did with Khouri.

Questions remain. Why did she and Toliopoulos leave America in this way? What were they running from? Or did the publishing deal offer them an opportunity to start a new life that they could only take by disguising their identity? And what, now, will she do?

Khouri's follow-up book, A Matter of Honour, is due for release in November, the big Christmas publishing season. But the real story of Norma Khouri, when she decides to tell it, could be just as fascinating as the fake one.